In the above-mentioned technical field, patent literature 1 discloses a technique which brakes a ball screw and sets 0 as a speed command to a servo motor at the same time when power supply is stopped.
On the other hand, patent literature 2 discloses a mechanism which prevents a free fall by an electromagnetic brake when the power supply is turned off.
In addition, patent literature 3 has disclosed a brake motor which stops the rotation of the motor shaft when no electric current is supplied.
Furthermore, patent literature 4 discloses a technique which controls a brake apparatus first by delaying a power shutoff command, thereby braking a gravity axis.